Rocking a backless peach Elie Saab dress and sky-high Jimmy Choos, the actress looked like she's already back to her pre-pregnancy body already after giving birth to son Bingham. She showed off her toned, tanned legs as she exited the car with her baby daddy in tow.

Kate Moss also dared to bare, choosing a backless, strapless number with a huge bow across her cleavage. Unlike Hudson, she left her rocker hubby, Jamie Hince, at home last night.

Stella herself opted for sequins, sporting a blue sparkly dress and a bun.

When you're the birthday girl, you're allowed to be the blingiest dressed at the bash!